1. Field of the Invention
The present invention relates to a damped restraining bearing for supercritically operating rotors, which encompasses the rotor with a definite gap and in response to radial rotor movement is activated or deactivated and whereby, for centering and restraining bearing relative to the rotor, the damping member of the restraining bearing is integrated with a damping bearing of the rotor.
The requirements which are set for a restraining bearing are that the bearing should respond rapidly when traversing critical speed range, that it should effectively dampen vibrations, that it should quickly disengage, and that it should not come into contact with the rotor during normal rotor operation.
2. Discussion of the Prior Art
In order to meet these requirements, it has been proposed that the restraining bearing be provided with a centering device which will center the restraining bearing relative to the rotor. Centering arrangements of this type render it possible to minimize the gap needed for unrestrictive operation between the rotor and the encompassing restraining bearing without causing the rotor to contact the restraining bearing during periods of smooth operation or during rated operation. This arrangement results in a bearing which is smooth running, and has a short response period as well as a rapid disengagement. The rapid disengagement is achieved because the centering action causes the restraining bearing to follow the rotor radially to some measure and to disengage much earlier during attentuation of vibrations than other known restraining bearings.
As a result of the forced guidance between the restraining bearing and the rotor, the arrangement will, apart from the advantage of rapid engagement and disengagement, also prevent a springing movement between rotor and restraining bearing during rated operation. This all contributes to safe and stable rotor operation with a minimal loss of input energy.